1. a living creature such as a dog or cat, that is not an insect, plant, bird, fish, or person: furry little animalswild/domestic/farm animals cattle, sheep, and other domestic animals The cosmetics have not been tested on animals. Beth is an animal lover (=someone who likes animals).

2. any living creature that is not a plant or a person: He can’t stand cruelty to animals of any sort. the animal welfare movement in Britain the enormous diversity of the animal kingdom

3. any living creature, including people: Man is a highly intelligent animal.

4. informal someone who behaves in a cruel, violent, or very rude way: Football hooligans are just animals.

5. a (very/completely/entirely) different animal informal something that is very different from the thing you have mentioned: Writing email is a very different animal from all other forms of writing.

6. a political/social etc animal informal someone who is interested in politics, in meeting other people etc: He is simply not a social animal.